Carbon fiber package and carbon fiber packed member

ABSTRACT

By using carbon fibers having a fineness of 25,000 deniers or more, the present invention provides a carbon fiber package including a cheese winding package or a coreless package in which an outside diameter of the package, a diameter of a bobbin or an inside diameter of the package, and a winding width are regulated in the specific ranges, a square-end type package in which a yarn width per fineness, wind angles at the start of winding and at the end of winding, and shifting of the yarn are regulated in the specific ranges, and a carbon fiber packed member in which an average bulk density is regulated in a specific range. Those carbon fiber packages and the carbon fiber packed member solve troubles and inconveniences during use, and also packages which have a high winding density and which do not break easily can be obtained.

TECHNICAL FIELD

The present invention relates to large packages and packed members ofcarbon fibers having particularly high fineness. Also, the presentinvention relates to packages of carbon fibers which are preciselyformed into a desired shape with high winding density so as not to beeasily broken, and to a method for producing the same.

BACKGROUND ART

There has been an increase in demand for the use of carbon fibers yearby year, and the demand has been shifting from premium usage, such asfor airplanes and sports equipment, to general industrial usage, such asfor construction, civil engineering, and energy.

In general industrial usage, particularly in processes such as weaving,filament winding, pultrusion, and the like for forming large structuralmaterials, a high fineness of approximately 100,000 deniers is required.Currently, in order to meet the demand described above, several yarns ofapproximately 7,000 to 20,000 deniers are combined to perform theformation.

Under the circumstances, if large packages having high fineness andheavy winding weight are obtained, the number of mountings of carbonfibers onto a higher processing apparatus will decrease and the creelunit will be more compact, and thus, great advantages are expected inthe use of carbon fibers.

It is a first object of the present invention, in order to satisfy thedemand described above, to provide a large package and a large packedmember in which carbon fibers having particularly high fineness arewound so that the occurrence of trouble or inconvenience will beprevented during use.

On the other hand, with respect to the formation by combination, sincethere are distances between combination units, irregular impregnation ofa resin may occur.

Also, since it is difficult to vertically layer fibers, fibers arehorizontally combined, and thus, the thickness of the yarn will be thethickness of the combination unit, i.e., 7,000 to 20,000 deniers, and itis difficult to increase the thickness of the yarn. In particular, whena large and thick forming member is produced, the number of layers andthe number of windings must be increased, resulting in disadvantage alsoin terms of formation time.

In other words, if a package of carbon fibers having a large number offilaments and large thickness is obtained, the number of mountings ofcarbon fibers onto a higher processing apparatus will decrease,formation time will be reduced, and the creel unit will be more compact,all of which are advantageous.

However, differing from general organic fibers, carbon fibers havesignificantly high Young's modulus and lack stretchability, and thereby,the range of windable tension is significantly small. If the tension istoo low, trouble may easily occur, such as breaking at both sides of aroll, deformation due to external force, and slipping of a yarn layerout of a bobbin, and if the tension is too high, damage to yarns duringwinding, and deterioration of unwinding characteristics occur, and thusit has been technically difficult to set winding conditions with respectto cheese winding.

With regard to a carbon fiber package that does not easily break or doesnot have much fuzz during unwinding, a package has been disclosed inJapanese Patent Publication No. 62-46468, in which the package is asquare-end type, and carbon fibers are taken up onto a bobbin with agiven wind ratio, the wind angles of the fibers at the start of windingand at the end of winding are 10° to 30° and 4° to 12° respectively, andthere is a shifting ratio of 50 to 150% of the average yarn width inrelation to the already wound yarn, every 1 to 9 traverses. This packageis a so-called “open-wind” package, in which, by minimizing the degreeof overlapping of yarns, fuzz during unwinding and broken yarns areprevented. In the case of a bobbin having a given size, if the“open-wind” is used, as the yarns having a large number of yarns, thatis, having high fineness, and having large thickness are wound, thespaces resulting from the overlap between yarns increase and theunevenness of the winding surface increases, and thus, the resultantpackage will be soft with low winding density, and both sides of theroll will easily bulge because the yarns are pushed out of the sides bymeans of winding tension and pressure on the winding surface (bearingpressure). Such a package may suffer broken winding duringtransportation, and because the bulge at both sides exceeds the lengthof a bobbin, the yarns may be damaged during the setup onto higherprocessing equipment.

It is the second object of the present invention, in view of theproblems described above, to provide the most suitable shaped packagewith respect to winding of carbon fiber yarns having particularly highfineness, in which high winding density is obtained and breakage doesnot easily occur, by basically changing the form of winding.

DISCLOSURE OF INVENTION

A carbon fiber package as a first mode of the present invention includesa cheese winding package, in which a carbon fiber of 25,000 deniers ormore is wound, and an outside diameter (D mm) of the package, a diameterof the bobbin (d mm), and a winding width (L mm) satisfy the followingrelationships:

d≧50,

20≦(D−d)/2≦400,

and

0.05≦(D−d)/2L≦0.7

A carbon fiber package as a second mode of the present inventionincludes a coreless package, in which a carbon fiber having a finenessof 25,000 deniers or more is wound, and an outside diameter (D mm) ofthe package, an inside diameter (di mm) of the package, and a windingwidth (L mm) satisfy the following relationships:

di≧50,

20≦(D−di)/2≦400,

and

0.05≦(D−di)/2L≦0.7

A carbon fiber package as a third mode of the present invention includesa square-end type package, in which a carbon fiber yarn having afineness of 25,000 deniers or more is wound onto a bobbin such that ayarn width per fineness ranges from 0.15×10^(×3) to 0.8×10^(×3)mm/denier, wind angles at the start of winding and at the end of windingare in the ranges of 10° to 30° and 3° to 15°, respectively, and afraction W₀ in a wind ratio W ranges from 0.12 to 0.88.

Also, in accordance with the present invention, a carbon fiber packedmember is provided, in which a continuous carbon fiber having a finenessof 25,000 deniers or more is packed in a container with an average bulkdensity in a range of 0.03 to 1.2 g/cm³.

BEST MODE FOR CARRYING OUT THE INVENTION

In carbon fiber packages in accordance with the first and the secondmodes of the present invention, preferably a winding density ranges from0.8 to 1.2 g/cm³. Herein, the winding density corresponds to “weight ofwound carbon fiber/apparent volume of wound carbon fiber”. Since thecheese winding package and the coreless package generally have a windingconfiguration in the shape of a doughnut-like cylinder, in the case of acheese winding package, the apparent volume of wound carbon fiber iscalculated as π·L(D²−d²)/4, and in the case of an coreless package, itis calculated as π·L(D²−di²)/4.

Also, preferably, carbon fibers to be wound are substantiallynon-twisted. If carbon fibers are twisted, it is difficult to wind upwith high winding density, and also slacks may occur on the bobbin owingto uneven tension, resulting in entanglement, which is disadvantageousduring unwinding. Herein, “substantially non-twisted” means that thenumber of twists is one turn or less per 1 m.

In carbon fiber packed members, preferably the carbon fibers to bepacked are also substantially non-twisted.

There is no limitation to the properties of carbon fibers in accordancewith the present invention. For example, tensile stress may range from200 to 700 kgf/mm² and tensile modulus may range from 15 to 50 tf/mm².

In carbon fiber packages in accordance with the present invention,carbon fibers as described above are wound in the form of a cheesewinding package or a coreless package, as a fiber bundle of thick carbonfibers having a fineness of 25,000 deniers or more, preferably of 30,000deniers or more, and more preferably of 40,000 to 100,000 deniers. Insuch a fiber bundle of thick carbon fibers, the number of filaments isgenerally 27,000 or more, preferably 40,000 or more, and more preferably55,000 to 150,000.

In the case of the cheese winding package, when a thick carbon fiberhaving a fineness of 25,000 deniers or more is wound into a package, ifd is 50 mm or less in relation to the outside diameter (D mm) of thepackage, the diameter of the bobbin (d mm), and the winding width (Lmm), the curvature of the carbon fiber in the innermost layer of thepackage decreases, and thereby, the fiber is drawn with tension duringunwinding, breaks of the fiber easily occur, and trouble easily occursduring higher processing. Also, with respect to thick carbon fibershaving a large number of filaments, since the fiber thickness increases,the trouble described above easily occurs. Also, since the wind angleincreases during winding, unevenness easily occurs, which is alsodisadvantageous. On the other hand, if d is 200 mm or more, spaceswithin the bobbin diameter increase, and volumetric efficiency of aportion occupied by carbon fibers as a cheese winding packagedeteriorates.

Also, if the winding thickness, i.e., (D−d)/2, is 20 mm or less, being alarge package becomes meaningless, and if it exceeds 400 mm, the packagebecomes too large and the weight increases too much, resulting indifficulty in handling.

Also, if a ratio of winding thickness to winding width, i.e., (D−d)/2L,is 0.05 or less, the volume of carbon fibers to be taken up decreases,and when securing the volume of carbon fibers to be taken up isattempted, the winding width increases extremely, which isdisadvantageous in use. If (D−d)/2L is 0.7 or more, the wind angles atthe ends increase and breaks easily occur. Consequently, in the carbonfiber package of cheese winding in accordance with the presentinvention, the following are the required ranges:

d≧50, preferably, 200≧d≧50,

20≦( D−d)/2≦400, preferably, 50≦( D−d)/2≦400,

and

 0.05≦(D−d)/2L≦0.7

On the other hand, with respect to the coreless package, similarly, whenforming a package by winding a carbon fiber having a fineness of 25,000deniers or more, the outside diameter (D mm) of the package, the insidediameter (di mm) of the package, i.e., the diameter of a bobbin that isused to form the package and extracted after the package is formed, andthe winding width (L mm) are set to satisfy the following relationships:

di≧50, preferably, 200≧di≧50,

20≦(D−di)/2≦400,

preferably,

50≦(D−di)/2≦400,

and

0.05≦(D−di)/2L≦0.7

Also, in the carbon fiber packed member in accordance with the presentinvention, a carbon fiber having a fineness of 25,000 deniers or more ispacked in a container, for example, a carton case, with an average bulkdensity in a range of 0.03 to 1.2 g/cm³, preferably 0.2 to 0.9 g/cm³.

The bulk density is calculated by dividing the weight of the carbonfiber packed in the container by the apparent volume occupied with thecarbon fiber. For example, when the carbon fiber is placed into arectangular parallelepiped carton case, the bulk density is calculatedby dividing the weight of the carbon fiber placed inside by the apparentvolume calculated based on the height of the filled carbon fiber.Specifically, a method of producing a packed member having a bulkdensity of 0.03 to 1.2 g/cm³ includes dropping carbon fibers from afixed roll into a carton case placed on a mount having a traversingmechanism. The traversing mechanism may be movable so as to draw asawtooth locus, or may move along the bottom face of the container. Ifthe bulk density is below 0.03 g/cm³, packaging efficiency deteriorates,and if the bulk density exceeds 1.2 g/cm³, yarns are excessivelypressed, resulting in unwinding failure during retrieval from thecontainer.

As described above, with respect to the packed member form also, bulkcontainment is possible, and a significantly convenient form of thickcarbon fibers can be provided for higher processing use.

In the third mode of a carbon fiber package in accordance with thepresent invention, preferably the wound yarn shifts from the yarn in theinner layer by 10 to 70% of the average yarn width every 1 to 9traverses.

In accordance with the third mode of carbon fiber packages, a carbonfiber having a fineness of 25,000 deniers or more is taken up onto abobbin such that the yarn width per fineness is in a range of 0.15×10⁻³to 0.8×10⁻³ mm/denier in order to form a square-end type package, inwhich the wind angles at the start of winding and at the end of windingare in the ranges of 10° to 30° and 3° to 15° respectively, and afraction W₀ in the wind ratio W is in a range of 0.12 to 0.88. In thismethod, it is also preferable that the yarn to be taken up be shiftedevery 1 to 9 traverses from the yarn already taken up at 10 to 70% ofthe average yarn width.

In accordance with the present invention, fineness of carbon fiber yarnsis represented as single filament fineness (denier) x number offilaments. As described above, although any fineness is acceptableprovided it is 25,000 deniers or more, since the single filamentfineness is generally 0.2 to 0.9 denier so as to function well as areinforcing fiber, the number of filaments is 28,000 or more.

The method for adjusting the fineness of the carbon fiber yarns to betaken up to 25,000 deniers or more includes a method of using anantecedent fiber having a high denier value as a starting material, amethod of combining several antecedent fibers having a small number offilaments during the burning process by the time of completion ofwinding, and a method of retrieving carbon fibers which have been woundfrom a creel, and winding them while combining, however, the method isnot limited to the above.

With regard to the method of regulating the yarn width in a range of0.15×10⁻³ to 0.8×10⁻³ mm/denier, although there are no limitations,generally a method of bringing yarns into contact with a grooved roller,a fixed guide, or the like, a method of adding a sizing agent in orderto prevent a single yarn from moving, and the like are combined. Also,the yarn width is represented as the mean between 5 points measured atdistances of 10 m. In accordance with the present invention, since thecarbon fiber yarns to be taken up have high denier values, it issubstantially difficult to select a yarn having a width exceeding theabove range.

The specific method for taking up the thick carbon fiber yarns havinghigh denier values include, for example, setting a bobbin for taking uponto a take-up spindle of a winder, using, as a traverse guide, aplurality of free rotation rolls having an outside diameter of 5 to 30mm placed in parallel which traverse parallel to the spindle axis, andwinding up carbon fiber yarns through the traverse guide. In such acase, if the wind angle at the start of winding is less than 10°,particularly less than 5° (the wind angle at the end of winding is lessthan 3°, particularly less than 2°), breaks easily occur, resulting indamage to yarns. More preferably, the wind angle at the start of windingranges from 12° to 17°, and the wind angle at the end of winding rangesfrom 4° to 7°.

When the carbon fiber yarns are taken up with a given wind ratio bymeans of the winder described above, it is preferable that yarns to betaken up uniformly extend onto the bobbin. The uniformity of positioningof yarns onto the bobbin is determined by a ratio of the number ofrevolutions by the bobbin to a traversing speed, i.e., a winding ratio.Specifically, the wind ratio W is represented by the following formula:

W=2L/(πD ₀ tan θ),

wherein L is a stroke of the guide of the winder traversingsubstantially parallel to the bobbin, i.e., a traverse width (mm), D₀ isan outside diameter of the bobbin (mm), and θ is a wind angle at thestart of winding.

If the wind ratio is an integer, the position of a yarn after onetraverse completely overlaps the previous position of the yarn, if thewind ratio deviates from an integer, the position after one traverseshifts from the previous position of the yarn in response to thedeviation. If the wind ratio is an integer, since a yarn continues to betaken up at the completely same position, yarns are localized, resultingin a non-uniform package with low winding density, which easily causesbreaking of the roll. In order to uniformly place the yarn to be takenup onto the bobbin, a decimal fraction deviated from the integer, i.e.,a fraction W₀ of the wind ratio W, is required to be in a range of 0.12to 0.88. Within this range, the positions of the yarns can be thoroughlychanged after each traverse, and thus, a package having high windingdensity can be formed. If W₀ is less than 0.12, or more than 0.88,because of it approaching an integer as described above, yarns arelocalized on the bobbin, resulting in an easily breakable package havinglow winding density.

Also, the yarns to be taken up onto the bobbin while being traversedoverlap on the substantially same position after several traverses, andat this stage, the width of shifting of the upper yarn from the loweryarn (the yarn already taken up in the inner layer) is referred to as ashifting distance, and the ratio of the width to the lower yarn width isreferred to as a shifting ratio. In the carbon fiber packages havinghigh denier values and large thickness in accordance with the presentinvention, the shifting ratio is also important, and when the shiftingratio is more than 70%, the proportion of parts in which yarns do notoverlap increases, and spaces are opened. The resultant package has lowwinding density, and thus, both sides may bulge because of tension andbearing pressure, both sides may be broken during winding, and even ifwinding is successfully completed to form a package, unwinding may occurduring transportation. On the other hand, when the shifting ratio isless than 10%, the overlapping area between the upper and the loweryarns excessively increases, and thus, fuzz of upper and lower yarns mayinterfere, and fuzz and broken yarns may occur during unwinding becauseof adhesion of a sizing agent. A more preferable range of the shiftingratio is 20 to 50%.

When such high denier carbon fibers are taken up around a bobbin bymeans of a general winder, the shifting ratio is determined by thepredetermined wind ratio and yarn width described above, and thedetermination is made in the same method as described in Japanese PatentPublication No. 62-46468.

EXAMPLES

The present invention will now be described with reference to morespecific examples.

Example 1

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m was wound around a bobbin with abobbin diameter of 80 mm at a winding width of 250 mm by means of awinder. The diameter D of the package was 400 mm, (D−d)/2 was 160, and(D−d)/2L was 0.64. Troubles such as off positions did not occur, and 30kg of wound product was successfully produced. The carbon fiber packagewas mounted onto a creel of a filament winder, and unwound with atensile force of 4 kg. Unwinding was completed without any trouble suchas twining.

Comparative Example 1

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m was wound around a bobbin with abobbin diameter of 30 mm at a winding width of 250 mm by means of awinder. Although troubles such as off position occurred with aprobability of 10%, 30 kg of wound product was produced. The diameter Dof the package was 500 mm, (D−d)/2 was 235, and (D−d)/2L was 0.94. Thecarbon fiber package was mounted onto a creel of a filament winder, andunwound with a tensile force of 4 kg. Partial yarn slacks occurredinside the yarns, and many void components were produced.

Example 2

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m, 20 kg by weight, was dropped from aheight of 3 m into a carton case with a dimension of 400 mm×400 mm×400mm which horizontally traverses so as to draw a locus of a square havinga side of 250 mm with a center of the carton case as the intersectionpoint of its diagonals in order to obtain a packed member. The tow wasreceived without leaning. The height of the filled carbon fiber in thepacked member was 160 mm, and the bulk density was 0.78 g/cm³. The towwas raised from the carton case, and pultrusion process was performedwith a pultruder. No trouble occurred during unwinding.

Comparative Example 2

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m, 20 kg by weight, was dropped from aheight of 3 m into a carton case with a dimension of 400 mm×400 mm×400mm which traverses the same way as in the example 2. During dropping,the tow was repeatedly pushed down to obtain a packed member. The heightof the filled carbon fiber in the packed member was 90 mm, and the bulkdensity was 1.4 g/cm³. The tow was raised from the carton case, and apultrusion process was performed with a pultruder. The tow rose whilebeing entangled with fuzz, and twined around the guide roll, andthereby, the process did not succeed.

Example 3

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m was wound around an extractable bobbinwith a bobbin diameter of 80 mm at a winding width of 250 mm by means ofa winder, and then the bobbin was extracted to form a coreless package.30 kg of wound product was successfully produced without any troublesuch as off positions. The diameter D of the package was 400 mm, di was80 mm, (D/di)/2 was 160, and (D di)/2L was 0.64. The carbon fiberpackage was mounted onto a creel of a pultruder, and unwound from theinnermost layer. Unwinding was completed without any trouble such astwining.

Comparative Example 3

A carbon fiber having 50,000 filaments (single yarn: 0.63 denier) and anareal weight (METSUKE) of 3.5 g/m was wound around an extractable bobbinwith a bobbin diameter of 30 mm at a winding width of 250 mm by means ofa winder, and then the bobbin was extracted to form a coreless package.Although troubles such as off positions occurred with a probability of15%, 30 kg of wound product was produced. The diameter D of the packagewas 500 mm, (D−di)/2 was 235, and (D−di)/2L was 0.94. The carbon fiberpackage was mounted onto a creel of a pultruder, and unwound from theinnermost layer. Partial yarn slacks occurred, and defects in resinimpregnation occurred.

Example 4 (Levels 1 through 7), Comparative Example (Levels 8 and 9)

A carbon fiber yarn having a fineness of 31,500 deniers (number offilaments: 50,000) was wound onto a paper tube having an inside diameterof 82 mm and a length of 280 mm at a winding width of 250 mm to form asquare-end type package. As shown in Tables 1 and 2, by changing thewind ratio, the shifting ratio was changed, and wound figures of thepackages obtained, the winding density, and unwinding characteristics byside unwinding were investigated. The package obtained at the level 2was excellent with respect to the wound figure and unwindingcharacteristics.

As is clear from the result of the example 4, if the requirementsregulated in the present invention are met, (particularly, at the level2, the fraction of the wind ratio), even if carbon fiber yarns have highfineness, packages having excellent winding density, wound figures, andunwinding characteristics can be obtained.

Example 5 (Levels 10 and 11)

A carbon fiber yarn having a fineness of 7,200 deniers (number offilaments: 12,000) was wound onto a paper tube having the same insidediameter and length as those in the example 1 while maintaining awinding width at 7 mm to form a square-end type package. As shown inTable 3, by changing the wind ratio, wound figures of the packagesobtained, the winding density, and unwinding characteristics by sideunwinding were investigated. All the packages obtained were inferiorwith respect to wound figures and unwinding characteristics.

TABLE 1 Level 1 Level 2 Level 3 Fineness (denier) 31,500 31,500 31,500Yarn width (mm) 12 12 12 shifting ratio/shifting distance 4/0.5 24/2.996/11.6 (%/mm) Wind angle (initial/final) 13.2/5.5 13.2/5.5 24.3/10 Windratio 8.2522 8.2788 4.3000 Traverse width (mm) 250 250 250 Outsidediameter of 82 82 82 bobbin (mm) Final diameter of wound 192 194 202package (mm) Winding density 1.02 1.00 0.90 Wound figure ExcellentExcellent Fair Unwinding characteristics Fair Excellent Fair Windingweight (kg) 6 6 6

TABLE 2 Level 4 Level 5 Level 6 Level 7 Level 8 Level 9 Fineness(denier) 31,500 31,500 31,500 31,500 31,500 31,500 Yarn width (mm) 25 612 12 12 12 shifting ratio/shifting distance 12/2.9 48/2.9 37/4.4 39/4.731/3.7 30/3.6 (%/mm) Wind angle (initial/final) 13.2/5.5 13.2/5.512.4/5.5 12.4/5.5 13.5/5 12.3/5 Wind ratio 8.2788 8.2788 8.1548 8.81678.1045 8.8959 Traverse width (mm) 250 250 250 250 250 250 Outsidediameter of bobbin (mm) 82 82 82 82 82 82 Final diameter of woundpackage (mm) 192 202 202 202 213 213 Winding density 1.02 0.90 0.90 0.900.80 0.80 Wound figure Excellent Fair Fair Fair Not good Not goodUnwinding characteristics Excellent Fair Fair Fair Not good Not goodWinding weight (kg) 6 6 6 6 6 6

TABLE 3 Level 10 Level 11 Fineness (denier) 7,200 7,200 Yarn width (mm)7 7 shifting ratio/shifting distance 53/3.7 51/3.6 (%/mm) Wind angle(initial/final) 13.5/5 12.3/5 Wind ratio 8.1045 8.8959 Traverse width(mm) 250 250 Outside diameter of bobbin (mm) 82 82 Final diameter ofwound package (mm) 202 202 Winding density 0.90 0.90 Wound figure FairFair Unwinding characteristics Fair Fair Winding weight (kg) 6 6

INDUSTRIAL APPLICABILITY

In accordance with carbon fiber packages of the present invention, acarbon fiber having high fineness can be formed into a proper largecheese winding or a coreless package such that no trouble occurs duringuse, and the carbon fiber can be provided inexpensively and in aextremely convenient shape for the usage requiring thick carbon fibers.

Also, in accordance with carbon fiber packed members of the presentinvention, a carbon fiber having high fineness can be packed in acontainer in volume so that no trouble occurs during use, and similarlyto the packages described above, carbon fibers can be providedinexpensively and in an extremely convenient shape for the usagerequiring thick carbon fibers.

Also, in accordance with the present invention, a carbon fiber yarnhaving particularly high fineness can be wound into a desirable packagewhich has high winding density, an excellent wound figure, and excellentunwinding characteristics and which is not easily broken.

What is claimed is:
 1. A carbon fiber package comprising a cheesewinding package comprising a carbon fiber of 25,000 deniers or more,wherein an outside diameter (D mm) of said package, a diameter of abobbin (d mm), and a winding width (L mm) satisfy the followingrelationships: d≧50, 20≦( D−d)/2≦400, and 0.05≦(D−d)/2L≦0.7.
 2. A carbonfiber package comprising a coreless package comprising a carbon fiberhaving a fineness of 25,000 deniers or more, wherein an outside diameter(D mm) of said package, an inside diameter (di mm) of said package, anda winding width (L mm) satisfy the following relationships: di≧50,20≧(D−di)/2≦400, and 0.05≦(D−di)/2L≦0.7.
 3. A carbon fiber packageaccording to claim 1 or 2, wherein the winding density ranges from 0.8to 1.2 g/cm³.
 4. A carbon fiber package comprising a square-end typepackage comprising a carbon fiber yarn having a fineness of 25,000deniers or more, said carbon fiber yarn being wound onto a bobbin suchthat a yarn width per fineness ranges from 0.15×10⁻³ to 0.8×10⁻³mm/denier, wherein wind angles at the start of winding and at the end ofwinding are in the ranges of 10° to 30° and 3° to 15°, respectively, anda fraction (W₀) in a wind ratio (W) ranges from 0.12 to 0.88.
 5. Acarbon fiber package according to claim 4, wherein the wound yarn shiftsfrom the wound yarn in the inner layer by 10 to 70% of an average yarnwidth every 1 to 9 traverses.
 6. A method for producing a carbon fiberpackage, comprising winding a carbon fiber yarn having a fineness of25,000 deniers or more onto a bobbin such that a yarn width per finenessranges from 0.15×10⁻³ to 0.8×10⁻³ mm/denier in order to form asquare-end package, wherein wind angles at the start of winding and atthe end of winding are in the ranges of 10° to 30° and 3° to 15°,respectively, and a fraction (W₀) in a wind ratio (W) ranges from 0.12to 0.88.
 7. A method for producing a carbon package according to claim6, wherein the wound yarn shifts from the wound yarn in the inner layerby 10 to 70% of an average yarn width every 1 to 9 traverses.
 8. Acarbon fiber packed member comprising a continuous carbon fiber having afineness of 25,000 deniers or more, said carbon fiber being packed in acontainer with an average bulk density in a range of 0.03 to 1.2 g/cm³.